they're among some 1,000 troops set to leave afghanistan this month. last month, president obama announced he is withdrawing 10,000 u.s. troops this year. the remaining 23,000 will leave by september of next year. in india, investigators in mumbai searched for clues in wednesday's triple bombing that killed 17 people and wounded 130 more. others demanded answers to how the city was attacked again, despite stepped-up security. we have a report narrated by john sparks of "independent television news." >> reporter: there was no warning. placed in the streets of mumbai the aftermath of one blast, a few hours later detectives began their investigation. a series of bombs detonated in rapid succession. this not the work of suicide bombers said the police. these were sophisticated devices triggered by timers. these the first attacks here since gunmen from pakistan laid siege to the city in 2008. the authorities were taken by surprise. nobody has claimed responsibility for the attacks, although security experts say a domestic group-- the indian mughadeen are pr